1. Field of the Invention
The present invention relates generally to a rotary converter for converting direct current to alternating current and, more particularly, is concerned with the current windings of the rotor of such a converter.
2. Description of the Prior Art
Generally, a dynamo is a rotating electric machine capable of converting electric energy into mechanical energy (a motor) or converting mechanical energy into electric energy (a generator). A dynamo consists of a rotor (that part of a dynamo which rotates) and a stator (that part of a dynamo which is stationary). Various dynamo designs and configurations are known for operating from or producing direct current and alternating current.
A rotary converter is a dynamo capable of operating from direct current and supplying alternating current, or vice verse. The rotor includes a shaft, an armature core, a commutator and slip rings. A single armature winding is wound around slots in the armature core and electrically connected to the commutator and the slip rings. The commutator acts as a rectifying device so that the current or voltage in the external circuit is unidirectional. When power is supplied to the converter, the rotor rotates in its magnetic field in known manner for dynamos. A discussion of characteristics of converters is presented in Chapter 44 of A. Puchstein, T. Lloyd and A. Conrad, Alternating-Current Machines (3rd ed. 1954), published by John Wiley & Sons, Inc. of New York.
U.S. Pat. No. 673,807 to Watson, issued in May of 1901, describes a controller for a rotary converter. The controller starts and regulates the running of a rotary converter.
U.S. Pat. No. 732,906 to Steinmetz, issued in July of 1903, described improvements to a dynamo-electric machine, particularly a rotary converter. A number of leads are connected to the armature winding of a converter which in normal operation carry currents of substantially the same phase.
U.S. Pat. No. 1,244,569 to Woodbridge, issued in October of 1917, describes a means for interconverting alternating and direct current. A magnetic structure is rotated by a motor causing direct current to pass through a circuit to produce magnetic flux. Reversal of the magnetic flux induces an electromotive force in coils which appears as alternating current electromotive force at collector rings. Alternating current is taken from the collector rings.
U.S. Pat. No. 1,284,370 to LaCour, issued in November of 1918, described a dynamo-electric machine adapted to serve as a motor-generator or as a generator of alternating and direct currents. The rotor winding serves as an armature winding for the direct current and at the same time as a short-circuited secondary winding for the alternating current.
U.S. Pat. No. 2,462,624 to Fletcher, issued in February of 1949, describes a voltage regulating system which includes a rotary converter.
U.S. Pat. No. 3,665,502 to Means, issued in May of 1972, describes an electrical motor-generator converter drawing energy from a low voltage battery to operate portable electric tools or the like rated for commercially standard utility voltages.
Kato Engineering Company (of North Mankato, Minn.), a corporate division of Reliance Electric Company (of Cleveland, Ohio), manufactures and sells rotary converters of various sizes for producing alternating current from direct current and distributes, for example, a catalog sheet RC-182 describing rotary converters.